While your action creation tutorial is good -- and no offense intended here -- IMO it has pretty much already been proven that upsizing in CS or CS2 via Bicubic smoother in one shot generates a better final result than taking the image up incrementally in bi-cubic or bi-cubic smoother due to no cumulative error effects.

IMO an even better method is to take it 20% over your final target size, sharpen, then take it down to final size via bicubic sharper.

Also, some of the third party programs like Q-Image and Genuine Fractals do a stellar job too. (Interestingly, Q-Image -- a printing program -- can have a greater or lesser final effect depending on what printer is being used...)

Here is an article I published on my website about night photography. I hope it'll be useful to some of you in this forum.

A Good Way to Super Size Your Digital Photoby Gary Hendricks

Have you ever wanted to blow up a small digital photo to a larger size? Well, as you may know, re-sampling an image to make it smaller is a simple task. However, blowing up an image is very difficult. You tend to lose details in the photo when you blow it up. This article will show you a technique for blowing up a photo with minimal loss in image quality. I’ll assume you’re using Adobe Photoshop CS.

Step 1: Duplicate the PhotoThe first and very critical step in this process is to backup your original photo. If you make a mistake in the process, at least you have a backup. In fact, this step should be done before any image editing task in general.

Step 2: Create an Enlarge ActionRight – once you’ve made a backup of the photo, access the Actions palette in Adobe Photoshop CS. At the top right of the Actions palette, you’ll see a small triangle. Click on it and select New Action from the menu that drops down.

Adobe Photoshop actions are wonderful. They allow you to record image editing tasks that you do on a regular basis so that you can save time. They are very similar to macros in Microsoft Excel.

Ok, under the New Action dialog box that pops up, enter a name for your action, the correct action set and assign a function key. Isn’t that neat, being able to assign a function key for an image editing task?

Next, you need to record the action for re-sampling the image to 110% of its original size. You can do this by performing the following:• Click on the Record button• Click on Image/Image Size on the toolbar• In the Image Size box that appears, ensure that the Resample Image box is checked.• Change the document size unit to Percent. • In the Document Size section of the, enter 110 for the width of the document.• Stop the recording of the action by clicking on the square button on the bottom left of the Actions palette.

Step 3: Repeat the ActionNow that you’ve recorded the action, let’s repeat on the image. Simply hit your assigned function key and voila, your image is re-sampled to 110% of its original size. See why we recorded the action? Recording repetitive tasks like this as an action is a huge time saver.

Continue hitting the function key until your photo reaches its desired size. I find that increasing the resolution by 10% each time is just right. However, it may depend on the photo – sometimes using 5% increments may be better.

ConclusionAs you can see, the above technique allows you to blow up and ‘super-size’ an image with minimal loss in image quality. I hope this tip will help you out some day. It’s very a very simple and effective technique which I employ sometimes if I need to have larger printouts.